Protector for lift seal of automobile hoist



g- 20, 1968 c. J. GOLDSMITH 3,397,421

PROTECTOR FOR LIFT SEAL OF AUTOMOBILE HOIST Filed May 17, 1966 INI/EN TOR ATTORNEYS United States Patent 3,397,421 PROTECTOR FOR LIFT SEAL OF AUTOMOBILE HOIST Cecil J. Goldsmith, 336 Wellington, Chicago, II]. 60657 Filed May 17, 1966, Ser. No. 550,784 4 Claims. (Cl. 15-210) ABSTRACT OF THE DISCLOSURE A flexible guard for protecting the lift seal of a floor mounted hoist is anchored to the floor at its outer edges and has its inner edges clamped in frictional wiping engagement with the plunger of the lift above the seal. Downward travel of the plunger draws the flexible guard into a collapsed condition characterized by an annular fold which collects foreign matter that would otherwise fall into the pit in which the hoist is mounted and holds it away from the plunger and its seal. Upward travel of the plunger carries the inner edge portions of the guard upwardly until it is extended into a tent configuration that causes the collected foreign matter -to fall down on the floor away from the pit.

This invention relates to means for protecting the lift seal for the hoist post or plunger of automatic car lifts, and is particularly concerned with gu'ard means serving as an automatic protector effective, when collapsed, to entrap foreign matte-r and effective, when extended, to shed the foreign matter, and also serving to exert a plunger wiping action adapted to prevent the plunger from carrying dirt or other foreign matter into contact with the lift seal during the operation of the car lift.

The hoist cylinder of most car li-fts is recessed within pits that open at the floor level, and dirt, water and grease often collect on the cylinder end and contact the hoist post or plunger, with the result that the plunger carries such foreign matter into contact with the lift seal as it is lowered into its pit. Any foreign matter on the plunger may cause deterioration of the plunger surface or of the lift seal, so that in time the seal loses its effectiveness. Moreover, the foreign matter collecting on the cylinder end also contacts the lift seal to cause deterioration thereof.

In accordance with the present invention, the guard is of suitable flexible material and has a peripheral anchoring edge secured to floor level regions surrounding the top of the pit in which the hoist is mounted, this peripheral anchoring edge incorporating an articulated frame having a separable joint to permit such frame to surround the plunger. The guard has a split collar providing an inner peripheral wiping edge defining an opening adapted to receive the plunger in limited frictional surface engagement therewith. The frictional engagement of the collar with the plunger allows the plunger to slide within the collar and causes the collar to wipe the outer surface of the plunger to clean it. The guard collar prevents any foreign substances from being carried by the plunger into contact with its seal, while the guard bridges the top of the pit to prevent foreign substances from collecting therein and contacting the lift seal.

Suitable structure by means of which the above mentioned and other advantages of the invention are attained will be fully described in the following specification, taken in conjunction with the accompanying drawings illustrating a preferred embodiment of the invention, in which:

FIGURE 1 is a fragmentary perspective view of a floor mounted car lift with its plunger shown in raised position, and with a guard embodying the invention applied thereto;

3,397,421 Patented Aug. 20, 1968 FIGURE 2 is a top plan view of the guard, with a portion broken away to show the frame member;

FIGURE 3 is a cross-sectional view, taken along the line 3-3 of FIGURE 2; and

FIGURE 4 is a cross-sectional view, taken along the line 4-4 of FIGURE 1.

Referring to the drawings, a vertical plunger or hoist post 10 for an automatic car lift is housed in 'a cylinder 11 that is recessed in and extends downwardly in a pit 12, such as is provided in the floor 13 of a service station. A lift seal S is associated with the upper end of the cylinder 11 and fits snugly around the periphery of the plunger to cooperate therewith in the usual fashion. An angle iron 14 is secured to the floor at the top of the pit is provided with apertures threaded to receive anchor bolts 15.

A guard in accordance with this invention is illustrated as comprising a flexible wraparound sheet 16 of leather, plastic, or any other suitable material, annu'larly encircling the plunger 'and spanning the top of the pit between the plunger and the floor to prevent dirt or other foreign matter from collecting in the pit where it can contact the lift seal S or the smooth slide surface of the plunger, consequently interfering with the slidable movement of the plunger and causing deterioration of its outer surface. The sheet 16 is comprised of four quarter panels 16P sewn together along overlapping edges to assume a smooth faced contour when extended to tent like form, as shown in FIGURE 1.

The sheet 16 has an inner peripheral edge defining a centrally disposed opening 17 adapted to receive the plunger. The opposite edges of the Wraparound sheet are adjacent to define a slot 18 extending from the opening 17 to the outer peripheral edge of the sheet which is to be anchored on the floor edge by means of the bolts 15. Opposite edges of the sheet defining the slot have interengageable snap fastener elements 19 for securing the edges together after the guard has been positioned around the plunger.

A split collar 21 is secured to the inner peripheral edge of the sheet 16 defining the opening 17 to be adjustably clamped upon the slide surface of the plunger. The collar 21 is sewed, or secured in any other suitable manner, to the sheet 16 with its opposite ends terminating adjacent the region of the slot 18. Two thin metal connector strips 22 and 23, respectively, are secured to the adjacent ends of the collar.

The strip 22 completely laps the corresponding end of the collar, but the strip 23 projects beyond the adjacent end of the collar so as to overlap a portion of the strip 22 when the sheet edges are abutted. A bracket 24 is rigidly secured to the strip 22 in transversely bridging spaced relation to permit the free end of the strip 23 to pass through the bracket and lie adjacent the strip 22.

The strip 23 is provided with a plurality of generally parallel side by side spaced slots 25 uniformly spaced apart longitudinally of the strip and extending transversely thereof at a slight angle. A screw 26 mounted for rotation in place in the bracket 24 has worm threads adapted to engage the slots 25. Rotation of the screw 26 carried by the bracket advances the strip 23 and the corresponding collar end to clamp the collar snugly around the plunger at appropriately selected frictional engagement. The worm and slot interengagement permits adjustment of the frictional engagement between the collar 21 and the plunger 10.

The outer peripheral edge of the wrap-around sheet 16 is secured to the floor 13 in any suitable manner. In the embodiment illustrated in the drawings, the outer edge of the sheet 16 is equipped with corner eyelets 16E associated with an articulated frame 27 comprised of individual strips 28 of wood, metal, plastic, or any other suitable material. Each strip 28 has an aperture 29 adjacent each end, and the adjoining ends of the strips are overlapped with the apertures in alignment with the corresponding eyelet 16E. The frame is secured to the floor by the bolts 15. One joint of the frame adjacent the outer end of the slot 18 is separable to permit application of the frame about the plunger 10. The frame may comprise two or more frame members hinged together in any suitable manner and having only one separable joint. In FIGURE 2, the ends of the frame members are held together for shipping and storage by wires 31.

In operation, the guard 16 acts with limited frictional engagement upon the slide surface of the plunger as determined by the clamping pressure applied by the collar 21 which impresses the sheet margin 16M in wiping engagement upon the plunger. The coverage of the guard across the top of the pit is complete to exclude foreign matter from accumulating in the pit and contacting the lift seal S or the plunger.

Any foreign particles depositing on the plunger above the guard are wiped onto the guard and thereby prevented from contact with the lift seal.

When the plunger is in the down position, the guard 16 assumes the folded contour illustrated in phantom lines in FIGURE 4. Foreign matter entering the top of the pit collects in the fold without contacting the lift seal S or the slide surface of the plunger.

When the plunger rises, the clamping collar 21 follows its travel until the guard is stretched smooth to the upstanding tent configuration illustrated in FIGURE 1 and in full lines in FIGURE 4. Continued travel of the plunger is permitted without disrupting the guard mounting. In this tent configuration the guard slopes sharply enough to shed any foreign matter previously collecting in its folds, while the plunger and guard were in the down position. The shed foreign matter can be removed during usual periodic floor cleaning.

This automatic trapping and shedding of the foreign matter prevents buildups and thereby reduces the problems associated with foreign matter accumulations.

Although a preferred embodiment of the invention has been described in considerable detail, it will be understood that the description thereof is intended to be illustrative, rather than restrictive, as many details of construction may be modified or changed without departing from the spirit or scope of the invention. Accordingly, it is not desired to be restricted to the exact structure described.

What is claimed is:

1. In a floor mounted hoist including a cylinder and plunger disposed in a pit, with an external lift seal mounted to the cylinder and cooperating with the plunger, a guard for protecting the lift seal from contact with foreign matter and including a flexible sheet annularly encircling the plunger in protective covering relation above the cylinder and having an inner peripheral edge equipped with clamping means establishing mechanical Wiping follower engagement upon the plunger and having an outer peripheral edge equipped with anchoring means to establish fixed engagement with the floor whereby downward travel of the plunger draws the flexible sheet into a collapsed condition characterized by an annular fold which collects foreign matter in isolated relation from both the lift seal and the plunger and upward travel of the plunger extends the flexible sheet into a tent configuration to shed the collected foreign matter.

2. A guard in accordance with claim 1 wherein said flexible sheet is of a wraparound type having opposite edges equipped with interengageable fastener means, and having said clamping means of adjustably expansible and contractible split collar structure.

3. A guard in accordance with claim 2 in which said clamping means includes metal strips at opposite ends of the split collar, a worm screw journaled in one of said strips and the other said strip having successive slots engageable by the worm screw to cooperate in varying the collar size.

4. A guard in accordance with claim 1 wherein said flexible sheet is of a wraparound type having opposite edges equipped with interengageable fastener means, having said clamping means of adjustably expansible and contractible split collar structure and having said anchoring means of articulated frame structure including a separable joint at the sheet edges connected by said fastener means.

References Cited UNITED STATES PATENTS 1,497,125 6/1924 Sorrells l5210.2 X 3,195,943 7/1965 Taylor et al. 8 X 3,334,706 8/1967 Dayson 1878.41

CHARLES A. WILLMUTH, Primal Examiner.

L. G. MACHLIN, Assistant Examiner. 

